Filter question
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Greetings everyone,
I just ordered my 1st HF transceiver this afternoon. (K3/100-F) The modes that I'm primarily in are as follows: SSB CW PSK31 AM - listening, not necessarily transmitting FM - listening only I've ordered the following roofing filters: 200hz ( primarily for PSK31 and other digital modes) 500hz ( primarily for general CW use) However, I'd like to be able to listen to AM broadcasts such as BBC, etc without compromising fidelity. Being that I only want to listen on AM and not necessarily transmit, and that I'd like to be able to listen to some FM as well, what filter do I need? (6khz and/or FM roofing filters, or will the KBPF3 general coverage RX filter module cover me?) I guess I'm a little confused as to what the KBPF3 is really providing. Thanks, - Bill _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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>From the K3 FAQs (see <http://www.elecraft.com/K3/K3FAQ.htm>)
~~~~ Q: I'm still not clear on the general-coverage (GC) receive option -- if it is indeed "optional" or available by default in a minimally configured radio. The basic radio, as well as the subreceiver, has a full array of ham-band-only filters at the front end. This is to ensure excellent performance in the ham bands. These filters are switched in by means of relays. The KBPF3 option is a small plug-in module that sits above the ham-band filters. It, too, has a number of filters switched in by relays. The difference is that these are wider filters, covering all of the area between the ham bands. But they share the same input/output path as the ham-band filters. When not selected, the GC filters have absolutely no effect on performance, thanks to a very careful layout that minimizes trace lengths. When you tune the radio well outside the ham bands, an appropriate GC filter is automatically selected by firmware. ~~~~ Hopes this helps -- at least with your KBPF3 question. Mark AD5SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by KB1PXD
Hi Bill,
The standard front end filters are tuned to the Ham bands only. Far enough outside of our bands the receiver will loose a lot of sensitivity because of this. To cover the regions used e.g. by broadcasters you need the KBPF3. This has nothing to do with the roofing filters. Depending upon your need to transmit AM and or listen to AM in a higher quality, you can use either the SSB filter for reception only (you listen to either the upper or lower sideband using SSB), or you need the 6kHz filter for "real" AM demodulation, which also gives you the ability to transmit AM. I wouldn't use the FM filter for this, but ymmv. For FM you will need the FM filter. Also if you want to add the second rx, don't forget that it needs its own filters. It does not share the KBPF3 or roofing filters with the main rx. Hope this helps, vy 73 de toby _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Hi Bill,
You need the KBPF3 filter if the BBC is not broadcasting in or near a Ham radio band. The BBC generally does not do this. You also need the KBPF3 if you want to listen to medium wave. You need the 6kHz filter to listen to AM with good fidelity. Conclusion: Imho, you will want to have both. vy 73 de toby Bill Kimura wrote: > Thank you Toby! Just so I'm clear, the 6kHz filter would allow me to > listen to > the UK BBC, etc. at full fidelity, and the KBPF3 module wouldn't be needed? > It may be helpful if you could provide me with an example of when I > would NEED > the KBPF3 module. > > Thanks again for the quick reply. > > - Bill _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Mark Bayern
Does the KBPF3 go into the RX module or the main board module? Ie do you
need two if you have the dual receivers? You probably wouldn't need dual RX out of band but just a wonder.... I guess the band passes would have to be on the RX modules or you wouldn't be able to get the two RX modules onto frequencies on two separate bands.... True? -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Mark Bayern Sent: Monday, February 18, 2008 1:55 PM To: Bill Kimura Cc: [hidden email] Subject: Re: [Elecraft] Filter question >From the K3 FAQs (see <http://www.elecraft.com/K3/K3FAQ.htm>) ~~~~ Q: I'm still not clear on the general-coverage (GC) receive option -- if it is indeed "optional" or available by default in a minimally configured radio. The basic radio, as well as the subreceiver, has a full array of ham-band-only filters at the front end. This is to ensure excellent performance in the ham bands. These filters are switched in by means of relays. The KBPF3 option is a small plug-in module that sits above the ham-band filters. It, too, has a number of filters switched in by relays. The difference is that these are wider filters, covering all of the area between the ham bands. But they share the same input/output path as the ham-band filters. When not selected, the GC filters have absolutely no effect on performance, thanks to a very careful layout that minimizes trace lengths. When you tune the radio well outside the ham bands, an appropriate GC filter is automatically selected by firmware. ~~~~ Hopes this helps -- at least with your KBPF3 question. Mark AD5SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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When I ordered my K3 and accessories I did not order the KBPF3 because I thot that was to add general coverage receive.... Now, I am thinking it is a bandpass filter to filter OUT non-ham band signals. That I need, so another order if my latter idea is correct. What is the function of the KBPF3????????? Do u need one for both main and sub receivers? 73Charles [hidden email] > From: [hidden email]> To: [hidden email]; [hidden email]> Subject: RE: [Elecraft] Filter question> Date: Mon, 18 Feb 2008 15:04:44 -0800> CC: [hidden email]> > Does the KBPF3 go into the RX module or the main board module? Ie do you> need two if you have the dual receivers? You probably wouldn't need dual RX> out of band but just a wonder.... I guess the band passes would have to be> on the RX modules or you wouldn't be able to get the two RX modules onto> frequencies on two separate bands.... True?> > -----Original Message-----> From: [hidden email]> [mailto:[hidden email]] On Behalf Of Mark Bayern> Sent: Monday, February 18, 2008 1:55 PM> To: Bill Kimura> Cc: [hidden email]> Subject: Re: [Elecraft] Filter question> > >From the K3 FAQs (see <http://www.elecraft.com/K3/K3FAQ.htm>)> > ~~~~> > Q: I'm still not clear on the general-coverage (GC) receive option --> if it is indeed "optional" or available by default in a minimally> configured radio.> > The basic radio, as well as the subreceiver, has a full array of> ham-band-only filters at the front end. This is to ensure excellent> performance in the ham bands. These filters are switched in by means> of relays.> > The KBPF3 option is a small plug-in module that sits above the> ham-band filters. It, too, has a number of filters switched in by> relays. The difference is that these are wider filters, covering all> of the area between the ham bands. But they share the same> input/output path as the ham-band filters. When not selected, the GC> filters have absolutely no effect on performance, thanks to a very> careful layout that minimizes trace lengths. When you tune the radio> well outside the ham bands, an appropriate GC filter is automatically> selected by firmware.> > ~~~~> > Hopes this helps -- at least with your KBPF3 question.> > > Mark AD5SS> _______________________________________________> Elecraft mailing list> Post to: [hidden email]> You must be a subscriber to post to the list.> Subscriber Info (Addr. Change, sub, unsub etc.):> http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm> Elecraft web page: http://www.elecraft.com> > _______________________________________________> Elecraft mailing list> Post to: [hidden email]> You must be a subscriber to post to the list.> Subscriber Info (Addr. Change, sub, unsub etc.):> http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm> Elecraft web page: http://www.elecraft.com_______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Hi Charles,
> When I ordered my K3 and accessories I did not order the KBPF3 > because I thot that was to add general coverage receive.... Correct. > Now, I am thinking it is a bandpass filter to filter OUT non-ham > band signals. No. It is a filter to allow non-ham frequencies. > What is the function of the KBPF3????????? Take a look at: <http://www.elecraft.com/K3/K3FAQ.htm#KBPF3> How is the KBPF3 bandpass filter used... <http://www.elecraft.com/K3/K3FAQ.htm#Subreceiver> I'm still not clear on the general-coverage (GC) receive option... <http://www.nabble.com/The-KBPF3-is-not-a-roofing-filter----it%27s-an-RF-band-pass-filter-module-to13820837.html#a13820837> The KBPF3 is not a roofing filter... <http://www.nabble.com/KBPF3-frequency-range-to14085227.html#a14085228> KBPF3 frequency range... <http://www.nabble.com/Ham-bands-vs-GC-receive-to14075801.html#a14075839> Ham bands vs GC receive... etc. etc. etc. > Do u need one for both main and sub receivers? If you want good sensitivity outside of the ham bands on both receivers, yes. If you want good sensitivity outside of the ham bands on one RX, you only need one KBPF3. If you are only want good sensitivity within the Ham bands, you do not need the KBPF3. vy 73 de toby _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Great advice response and vy clear.... Answer is "no" the KBPF3 does not help the ham bands. So, it is not a band pass filter in the usual sense of an ICE 419 which rejects sigs outside one ham band (switchable). BIG thanks!!!! 73Charles [hidden email] > Date: Tue, 19 Feb 2008 11:26:02 +0100> From: [hidden email]> To: [hidden email]> CC: [hidden email]; [hidden email]; [hidden email]; [hidden email]> Subject: Re: [Elecraft] KBPF3> > Hi Charles,> > > When I ordered my K3 and accessories I did not order the KBPF3 > > because I thot that was to add general coverage receive....> > Correct.> > > Now, I am thinking it is a bandpass filter to filter OUT non-ham > > band signals.> > No. It is a filter to allow non-ham frequencies.> > > > What is the function of the KBPF3?????????> > Take a look at:> > <http://www.elecraft.com/K3/K3FAQ.htm#KBPF3>> How is the KBPF3 bandpass filter used...> > <http://www.elecraft.com/K3/K3FAQ.htm#Subreceiver>> I'm still not clear on the general-coverage (GC) receive option...> > <http://www.nabble.com/The-KBPF3-is-not-a-roofing-filter----it%27s-an-RF-band-pass-filter-module-to13820837.html#a13820837>> The KBPF3 is not a roofing filter...> > <http://www.nabble.com/KBPF3-frequency-range-to14085227.html#a14085228>> KBPF3 frequency range...> > <http://www.nabble.com/Ham-bands-vs-GC-receive-to14075801.html#a14075839>> Ham bands vs GC receive...> > etc. etc. etc.> > > > Do u need one for both main and sub receivers?> > If you want good sensitivity outside of the ham bands on both receivers, yes.> > If you want good sensitivity outside of the ham bands on one RX, you > only need one KBPF3.> > If you are only want good sensitivity within the Ham bands, you do not > need the KBPF3.> > > vy 73 de toby> _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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